Various types of systems for drying grain and like materials are known. The systems described in the following listed U.S. patents are illustrative of the various known types of systems: U.S. Pat. Nos. 4,599,809; 4,896,795; 4,712,311; 4,253,244; 4,152,840; 4,149,844; 4,255,869; 4,558,523; 3,946,496; 4,555,858; 4,257,169; 4,916,830; 4,004,351; 4,490,924; 4,372,053; 4,386,471; 3,795,984; 4,253,243; 4,471,424; 4,696,115; 4,660,298; 4,513,759; 4,302,888; 3,787,985; 3,948,277; 4,434,563; 4,750,273; and, 4,578,878. This listing is not intended as a representation that a thorough search of all pertinent prior art has been conducted, or that no better prior art exists. Nor does this listing constitute an admission that any of the above-identified patents is pertinent prior art.